Blood filter



FIG. 1 is a front, top, right side perspective view of a blood filter showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side elevational view thereof, the left side elevational view being a mirror image;

FIG. 5 is a top plan view thereof, the bottom plan view being a mirror image; and,

FIG. 6 is a sectional view taken along line 6--6 of FIG. 2. 

The ornamental design for a blood filter, as shown and described. 